sealed class PaymentMethod
sealed class CreditCard : PaymentMethod()

data class Card(val field:String): CreditCard()
data class UntokenizedCard(val field:String,val field2String): CreditCard()

// How to parse this request  to accept either Card/ UntokenizedCard objects
data class RetrofitRequest(something:Something)

"credit-card" : {
      "cvc-code" : "999",
      "expiration-date" : "12/2019",
      "number" : "1234 1234 1234 1234",
      "type" : "VISA"
   }
or 
"credit-card" : {
      "identifier": "AAAA"
      "cvc-code" : "999"
   }

class PaymentMethodAdapter : JsonAdapter.Factory {
    override fun create(type: Type, annotations: MutableSet<out Annotation>, moshi: Moshi): JsonAdapter<*>? {
        if (!Types.getRawType(type).isAssignableFrom(PaymentMethod::class.java)) {
            return null
        }

        return object: JsonAdapter<PaymentMethod>() {
            private val tokenizedCardAdapter = moshi.adapter<TokenizedCard>(TokenizedCard::class.java)
            private val unregisteredCardAdapter = moshi.adapter<UnregisteredCard>(UnregisteredCard::class.java)

            override fun toJson(jsonWriter: JsonWriter, value: PaymentMethod?) {
                requireNotNull(value)
                when (value) {
                    is TokenizedCard -> { tokenizedCardAdapter.toJson(jsonWriter,value) }
                    is UnregisteredCard -> { unregisteredCardAdapter.toJson(jsonWriter,value) }
                }
            }

            override  fun fromJson(reader: JsonReader): PaymentMethod? {
                TODO()
            }
        }
    }
}

suspend

data class A (
    list: ListOf(B)
)

data class B ( ... )

id INTEGER AS Int PRIMARY KEY NOT NULL

id: Int?

INSERT INTO table VALUES ?

FOREIGN KEY